In large distribution applications, sortation conveying systems are often used to fulfill orders of intermingled articles such as assortments of books, video cassette containers, packaged software, compact disk containers, etc. Workers load articles into the system and the articles are conveyed in single file on a core conveyor belt for the sortation conveying system. As the assorted articles move along the core conveyor belt in single file, the system reads bar code information on each respective article. Based on this information, a programmable computer instructs the system with respect to further downstream processing and assorting of articles into various outgoing orders. The downstream end of the sortation conveying system normally includes a system of computer controlled diverting gates that divert articles into appropriate discharge stacking stations for outgoing orders. Outgoing orders typically contain 100 or more articles. Workers take the articles from the respective stacking station, and pack the orders for distribution. If an article is loaded onto the core conveyor and is not needed for any of the outgoing orders, it is diverted into a leftover bin. These types of sortation conveying systems are particularly effective in large distribution applications because order fulfillment and sortation are electronically integrated, thus substantially reducing the likelihood of human error in fulfilling the orders.
It is important to note that stacking the sorted articles minimizes damage to the articles being handled. For example, diverting articles into bins creates substantially more damage than stacking the orders.
The present invention was developed by the assignee of this application in order to foster more efficient mechanical handling of articles in the discharge stacking stations. In particular, it was desirable to develop a stacking station that was able to efficiently handle and move articles with the articles standing upright on edge, and without allowing the articles to tip. Importantly, it is desirable that this be done at speeds sufficiently high so that the operation of the stacking stations does not create an efficiency bottleneck for the overall system. In addition, it is desirable that the stacking stations dispense orders in a manner that is convenient and accessible for workers to unload.